Imminent in a menacing way (7)
I believe the answer is:
looming
'imminent in a menacing way' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for looming that I've seen before include "Appearing threateningly" , "Hovering as something dark or threatening" , "Appearing indistinctly" , "Coming into view" , "Imminent in a menacing way" .)